# How do you factor 15x +45x^2?

$15 x + 45 {x}^{2} = 15 x \left(1 + 3 x\right)$
$15 x$ is in both terms, divide it out.
$15 x + 45 {x}^{2} = 15 x \left(1 + 3 x\right)$